Amplification of One- and Two-Photon Excited Emission of a Stilbazolium Dye–Laponite Hybrid

Non-linear optics plays a pivotal role across diverse applications, such as biomedicine, photonics, optoelectronics, and surface science. Recently, the non-linear optical characteristics of two-dimensional materials and organic–inorganic hybrid materials have been of particular interest. Here, we demonstrate the first evidence that Laponite can be a highly promising medium to intensely enhance the efficiency of the emission of a stilbazolium dye by both one-photon and two-photon excitations. This can be attributed to the interaction of the dye with the ionic microenvironment of Laponite. Our findings illustrate that the adsorption of this cationic dye onto the negatively charged faces of Laponite platelets in an aqueous dispersion results in a remarkable enhancement in fluorescence intensity, by up to a factor of 15. A series of experiments, including viscosity measurements, ionic conductivity measurements, dynamic light scattering, and small-angle X-ray scattering, were conducted to explore the intricate interaction between the organic dye and Laponite. The results uncover alterations in the local molecular environment of the dye due to its interaction with Laponite, leading to the suppression of non-radiative recombination pathways. Consequently, both the linear and nonlinear fluorescence in this novel hybrid system increase, which has the potential to impact applications in biosensors, fluorescent probes, imaging, etc., requiring highly emissive properties.